The present inventive subject matter relates generally to the art of image analysis. Particular but not exclusive relevance is found in connection with the analysis of images captured by red light and/or other traffic enforcement cameras. Accordingly, the present specification makes specific reference thereto. It is to be appreciated however that aspects of the present inventive subject matter are also equally amenable to other like applications.
For images captured with red light, traffic enforcement and/or other like automated and/or unattended cameras it can be desirable to automatically detect a persistent change in the scene observed by the camera. For example, it may be desirable to detect a stalled and/or abandoned vehicle on a roadway or at an intersection or it may be desirable to detect abandoned luggage or packages left suspiciously at an airport or other location. In these examples, the abandoned vehicle or luggage represents a persistent change in the scene. In another example, foliage growth obstructing a view of the camera may represent a persistent change in the scene. Detecting such changes can be particularly challenging in outdoor scenes due to naturally varying illumination, e.g., caused by changes in sun position and/or the weather.
The problem is further complicated when the scene of interest contains relatively inconsequential dynamic variations that are not particularly significant from a detection perspective in the particular application at hand. For example, at a traffic intersection, vehicles may drive through the scene at various times and are part of a dynamically varying “background.” Likewise, at an airport, people may be walking through the scene at various times. However, such transient changes and/or variations in the background of the scene may not be of particular interest. Yet, more persistent changes such as a stalled vehicle or abandoned piece of luggage (referred to as “foreground” changes in the scene) may be of interest.
Certain camera monitoring systems and/or techniques have been developed which function to detect transient changes in an observed scene, but the detection of persistent changes in a dynamically varying scene is largely performed by technicians and/or other assigned personnel manually examining images of the scene obtained by the camera. Such manual processes can be undesirably labor intensive and/or prone to human error.
Accordingly, a new and/or improved method, system and/or apparatus for detecting persistent changes in a naturally varying scene observed by a camera is disclosed which addresses the above-referenced problem(s) and/or others.